21211332 has 12 divisors (see below), whose sum is σ = 49493136. Its totient is φ = 7070440.

The previous prime is 21211319. The next prime is 21211339. The reversal of 21211332 is 23311212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21211339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 883794 + ... + 883817.

It is an arithmetic number, because the mean of its divisors is an integer number (4124428).

Almost surely, 2^21211332 is an apocalyptic number.

It is an amenable number.

21211332 is an abundant number, since it is smaller than the sum of its proper divisors (28281804).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21211332 is a wasteful number, since it uses less digits than its factorization.

21211332 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1767618 (or 1767616 counting only the distinct ones).

The product of its digits is 72, while the sum is 15.

The square root of 21211332 is about 4605.5761854517. The cubic root of 21211332 is about 276.8148049428.

Adding to 21211332 its reverse (23311212), we get a palindrome (44522544).

The spelling of 21211332 in words is "twenty-one million, two hundred eleven thousand, three hundred thirty-two".